Some examples of shape key sculpting vs lattice?
Shape keys and lattice are 2 completely different things in my opinion, generally you should think about shape keys (or bones) when you want to animate small details of your mesh, and Lattice (or Mesh Deform or Surface Deform modifiers) when you want to deform the whole mesh or a large part of your mesh.
Also, lattice is particular as it deforms only the part of the mesh that it contains, here is the kind of thing that you can do with Lattice that you couldn't do with shapekeys or Mesh Deform or Surface Deform:

Here is what it would give to have a boolean object that is latticed: